1 /* $NetBSD: xen_ipi.c,v 1.42 2023/11/06 17:01:07 rin Exp $ */ 2 3 /*- 4 * Copyright (c) 2011, 2019 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Cherry G. Mathew <cherry (at) zyx.in> 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> /* RCS ID macro */ 33 34 /* 35 * Based on: x86/ipi.c 36 */ 37 38 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.42 2023/11/06 17:01:07 rin Exp $"); 39 40 #include "opt_ddb.h" 41 42 #include <sys/types.h> 43 44 #include <sys/atomic.h> 45 #include <sys/cpu.h> 46 #include <sys/mutex.h> 47 #include <sys/device.h> 48 #include <sys/xcall.h> 49 #include <sys/ipi.h> 50 #include <sys/errno.h> 51 #include <sys/systm.h> 52 53 #include <x86/fpu.h> 54 #include <machine/frame.h> 55 #include <machine/segments.h> 56 57 #include <xen/evtchn.h> 58 #include <xen/intr.h> 59 #include <xen/intrdefs.h> 60 #include <xen/hypervisor.h> 61 #include <xen/include/public/vcpu.h> 62 63 #ifdef DDB 64 extern void ddb_ipi(struct trapframe); 65 static void xen_ipi_ddb(struct cpu_info *, struct intrframe *); 66 #endif 67 68 static void xen_ipi_halt(struct cpu_info *, struct intrframe *); 69 static void xen_ipi_synch_fpu(struct cpu_info *, struct intrframe *); 70 static void xen_ipi_xcall(struct cpu_info *, struct intrframe *); 71 static void xen_ipi_hvcb(struct cpu_info *, struct intrframe *); 72 static void xen_ipi_generic(struct cpu_info *, struct intrframe *); 73 static void xen_ipi_ast(struct cpu_info *, struct intrframe *); 74 static void xen_ipi_kpreempt(struct cpu_info *ci, struct intrframe *); 75 76 static void (*xen_ipifunc[XEN_NIPIS])(struct cpu_info *, struct intrframe *) = 77 { /* In order of priority (see: xen/include/intrdefs.h */ 78 xen_ipi_halt, 79 xen_ipi_synch_fpu, 80 #ifdef DDB 81 xen_ipi_ddb, 82 #else 83 NULL, 84 #endif 85 xen_ipi_xcall, 86 xen_ipi_hvcb, 87 xen_ipi_generic, 88 xen_ipi_ast, 89 xen_ipi_kpreempt 90 }; 91 92 static int 93 xen_ipi_handler(void *arg, struct intrframe *regs) 94 { 95 uint32_t pending; 96 int bit; 97 struct cpu_info *ci; 98 99 ci = curcpu(); 100 101 KASSERT(ci == arg); 102 pending = atomic_swap_32(&ci->ci_ipis, 0); 103 104 KDASSERT((pending >> XEN_NIPIS) == 0); 105 while ((bit = ffs(pending)) != 0) { 106 bit--; 107 pending &= ~(1 << bit); 108 ci->ci_ipi_events[bit].ev_count++; 109 if (xen_ipifunc[bit] != NULL) { 110 (*xen_ipifunc[bit])(ci, regs); 111 } else { 112 panic("xen_ipifunc[%d] unsupported!\n", bit); 113 /* NOTREACHED */ 114 } 115 } 116 117 return 0; 118 } 119 120 /* Must be called once for every cpu that expects to send/recv ipis */ 121 void 122 xen_ipi_init(void) 123 { 124 cpuid_t vcpu; 125 evtchn_port_t evtchn; 126 struct cpu_info *ci; 127 char intr_xname[INTRDEVNAMEBUF]; 128 129 ci = curcpu(); 130 131 vcpu = ci->ci_vcpuid; 132 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 133 134 evtchn = bind_vcpu_to_evtch(vcpu); 135 ci->ci_ipi_evtchn = evtchn; 136 137 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 138 139 snprintf(intr_xname, sizeof(intr_xname), "%s ipi", 140 device_xname(ci->ci_dev)); 141 142 if (event_set_handler(evtchn, 143 __FPTRCAST(int (*)(void *), xen_ipi_handler), ci, IPL_HIGH, 144 NULL, intr_xname, true, ci) == NULL) { 145 panic("%s: unable to register ipi handler\n", __func__); 146 /* NOTREACHED */ 147 } 148 149 hypervisor_unmask_event(evtchn); 150 } 151 152 static inline bool __diagused 153 valid_ipimask(uint32_t ipimask) 154 { 155 uint32_t masks = XEN_IPI_GENERIC | XEN_IPI_HVCB | XEN_IPI_XCALL | 156 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 157 XEN_IPI_HALT | XEN_IPI_AST | XEN_IPI_KPREEMPT; 158 159 if (ipimask & ~masks) { 160 return false; 161 } else { 162 return true; 163 } 164 165 } 166 167 int 168 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 169 { 170 evtchn_port_t evtchn; 171 172 KASSERT(ci != NULL && ci != curcpu()); 173 174 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 175 return ENOENT; 176 } 177 178 evtchn = ci->ci_ipi_evtchn; 179 180 KASSERTMSG(valid_ipimask(ipimask) == true, 181 "xen_send_ipi() called with invalid ipimask\n"); 182 183 atomic_or_32(&ci->ci_ipis, ipimask); 184 hypervisor_notify_via_evtchn(evtchn); 185 186 return 0; 187 } 188 189 void 190 xen_broadcast_ipi(uint32_t ipimask) 191 { 192 struct cpu_info *ci, *self = curcpu(); 193 CPU_INFO_ITERATOR cii; 194 195 KASSERTMSG(valid_ipimask(ipimask) == true, 196 "xen_broadcast_ipi() called with invalid ipimask\n"); 197 198 /* 199 * XXX-cherry: there's an implicit broadcast sending order 200 * which I dislike. Randomise this ? :-) 201 */ 202 203 for (CPU_INFO_FOREACH(cii, ci)) { 204 if (ci == NULL) 205 continue; 206 if (ci == self) 207 continue; 208 if (ci->ci_data.cpu_idlelwp == NULL) 209 continue; 210 if ((ci->ci_flags & CPUF_PRESENT) == 0) 211 continue; 212 if (ci->ci_flags & (CPUF_RUNNING)) { 213 if (0 != xen_send_ipi(ci, ipimask)) { 214 panic("xen_ipi of %x from %s to %s failed\n", 215 ipimask, cpu_name(curcpu()), 216 cpu_name(ci)); 217 } 218 } 219 } 220 } 221 222 /* MD wrapper for the xcall(9) callback. */ 223 224 static void 225 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 226 { 227 KASSERT(ci == curcpu()); 228 KASSERT(ci != NULL); 229 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_vcpuid, NULL)) { 230 panic("%s shutdown failed.\n", device_xname(ci->ci_dev)); 231 } 232 233 } 234 235 static void 236 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 237 { 238 KASSERT(ci != NULL); 239 KASSERT(intrf != NULL); 240 241 panic("%s: impossible", __func__); 242 } 243 244 #ifdef DDB 245 static void 246 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 247 { 248 KASSERT(ci != NULL); 249 KASSERT(intrf != NULL); 250 251 #ifdef __x86_64__ 252 ddb_ipi(intrf->if_tf); 253 #else 254 struct trapframe tf; 255 tf.tf_gs = intrf->if_gs; 256 tf.tf_fs = intrf->if_fs; 257 tf.tf_es = intrf->if_es; 258 tf.tf_ds = intrf->if_ds; 259 tf.tf_edi = intrf->if_edi; 260 tf.tf_esi = intrf->if_esi; 261 tf.tf_ebp = intrf->if_ebp; 262 tf.tf_ebx = intrf->if_ebx; 263 tf.tf_ecx = intrf->if_ecx; 264 tf.tf_eax = intrf->if_eax; 265 tf.tf_trapno = intrf->__if_trapno; 266 tf.tf_err = intrf->__if_err; 267 tf.tf_eip = intrf->if_eip; 268 tf.tf_cs = intrf->if_cs; 269 tf.tf_eflags = intrf->if_eflags; 270 tf.tf_esp = intrf->if_esp; 271 tf.tf_ss = intrf->if_ss; 272 273 ddb_ipi(tf); 274 #endif 275 } 276 #endif /* DDB */ 277 278 static void 279 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 280 { 281 KASSERT(ci != NULL); 282 KASSERT(intrf != NULL); 283 284 xc_ipi_handler(); 285 } 286 287 static void 288 xen_ipi_ast(struct cpu_info *ci, struct intrframe *intrf) 289 { 290 KASSERT(ci != NULL); 291 KASSERT(intrf != NULL); 292 293 aston(ci->ci_onproc); 294 } 295 296 static void 297 xen_ipi_generic(struct cpu_info *ci, struct intrframe *intrf) 298 { 299 KASSERT(ci != NULL); 300 KASSERT(intrf != NULL); 301 ipi_cpu_handler(); 302 } 303 304 static void 305 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 306 { 307 KASSERT(ci != NULL); 308 KASSERT(intrf != NULL); 309 KASSERT(ci == curcpu()); 310 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 311 312 hypervisor_force_callback(); 313 } 314 315 static void 316 xen_ipi_kpreempt(struct cpu_info *ci, struct intrframe * intrf) 317 { 318 softint_trigger(1 << SIR_PREEMPT); 319 } 320 321 #ifdef XENPV 322 void 323 xc_send_ipi(struct cpu_info *ci) 324 { 325 326 KASSERT(kpreempt_disabled()); 327 KASSERT(curcpu() != ci); 328 if (ci) { 329 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 330 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 331 } 332 } else { 333 xen_broadcast_ipi(XEN_IPI_XCALL); 334 } 335 } 336 337 void 338 cpu_ipi(struct cpu_info *ci) 339 { 340 KASSERT(kpreempt_disabled()); 341 KASSERT(curcpu() != ci); 342 if (ci) { 343 if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) { 344 panic("xen_send_ipi(XEN_IPI_GENERIC) failed\n"); 345 } 346 } else { 347 xen_broadcast_ipi(XEN_IPI_GENERIC); 348 } 349 } 350 #endif /* XENPV */ 351
Indexes created Tue Sep 30 20:09:53 GMT 2025